1: 96 percent / NaBH4; CeCl3*7H2O / methanol / 2 h / 20 °C 2: 82 percent / CaH2; titanium tetraisopropoxide; tert-butyl hydroperoxide / L-(+)-diisopropyltartrate; molecular sieves 3 Angstroem / CH2Cl2 / 48 h / -20 °C View Scheme